1. Field of the Invention
The present invention relates generally to testing of integrated circuits (IC) and more specifically to a method and apparatus for testing I/O paths of a integrated circuit.
2. Related Art
An input/output (I/O) path generally refers to a signal path between a pad (which provides interface to external devices/components) and internal functional logic portion of an integrated circuit (IC). The internal functional logic portion generally provides the desired processing and uses the I/O paths for receiving input signals and sending the output signals.
Each I/O path may be viewed as containing a conductive portions (i.e., intended for merely transferring the signal without delay/distortion, etc.) and components such as buffers (which provide translation of voltage/current levels, impedance matching, power output, etc.), passive elements (inductors, capacitors, etc.).
There is a general need to ensure the desired operation of I/O paths. For example, it may be necessary to ensure that the I/O path accurately transfers the signals received on a pad to the internal functional logic portion and in the other direction as well. Further more, it may be desirable to ensure that the transfer of the signals occur within a desired time specification. Thus, there is a general need to test components of I/O paths as well.
In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.